1. Field of the Invention
The present invention relates to a revised interlocking tab of a zipper, and particularly to an improvement on an interlocking tab of a zipper, with which a curve shaped zipper is possible to be formed easily and smoothly by way of a stretchy cloth tape and engaging teeth possible to be elongated.
2. Description of Related Art
The zipper is an interlocking device popularly used in out daily so that it can be seen easily in the ready-made clothes, hand bags, sleep bags, tents, . . . , and so on. The zipper provides advantages such as being conveniently operated and being durable, and these are the reason why it is so popularly used and replaces many of traditional interlocking device.
Mostly, there are three types of zippers available based on the material thereof and they are zippers respectively made of metal, nylon, and fiber-reinforced plastics. Usually, a zipper is composed of an interlocking tab and a slier and the interlocking tab provides two opposite lines of teeth for engaging with each other and a cloth tape extending laterally from the engaging teeth for being attached to an article by way of sewing. The engaging teeth on a metal zipper and on a zipper of fiber-reinforced plastics are independently disposed and neighboring teeth are equally spaced apart from each other such that two opposite lines of teeth can engage with each other. As for the nylon zipper, the teeth thereof are made from nylon or polyester filament being heat up and curled so as to form continuous spirals or coils for being able to engage with each other oppositely. Hence, the fabrication of the interlock tab on the nylon zipper is after the spirals or coils are formed before the cloth tape can be sewed onto an article.
Although the conventional zipper can interlock two part of an article, there is a slight imperfection that the zipper is limited to be formed as a shape of straight line. That is, it is hard to form a shape of curve for the zipper while -the sewing work is conducted, especially for the metal zipper and the zipper of fiber-reinforced plastics. The engaging teeth, on the metal zipper and the zipper of fiber-reinforced plastics have been fixed in shape such that it is very limited for the fixed teeth to be bent. As for the engaging teeth on the nylon zipper, although the shape of continuous coils and the flexure of the material make the engaging teeth possible to be bent appropriately, a fixed length of cloth tape makes the sewing work unable to be done easily.
The preceding bottleneck with regard to the zipper being used or being worked has restricted the product design to avoid the joining of curve and work with straight line only. However, the curve shape is inevitable for the product design or the fabrication of ready-made clothes so that how to obtain an interlocking tab being formed with curve shape is a subject worth us to develop so as to solve the problem of conventional zipper.
An object of the present invention is to provide a revised interlocking tab of a zipper, with which a curve shape for the zipper can be performed during being worked in addition to the shape of straight line due to a cloth tape thereof providing a feature of stretchy and engaging teeth thereof possible to be elongated.